TreeView binding and TreeView binding

TreeView binding and TreeView binding

Recently, I encountered the TreeView database binding problem. It did take me a few days, especially the step-by-step binding of multi-level nodes. In the first place, I found that all the page loading was stuck, this is really a headache. So let's take a look at what you need, so as not to let everyone go.

1. Only data tables of the first-level nodes are bound.

Some code:

Protected void treeviewbind () {string sqlstr = ConfigurationManager. appSettings ["constr"]; SqlConnection con = new SqlConnection (sqlstr); con. open (); string strfac = "select * from tDepartment"; SqlDataAdapter ada = new SqlDataAdapter (strfac, con); DataTable dt = new DataTable (); ada. fill (dt); string id = "Department"; string text = "Department"; Bind_ TV (dt, id, text); dt. dispose (); ada. dispose (); con. close ();} protected void Bind_ TV (DataTable dt, string id, string text) // recursive binding of TreeView {DataView dv = new DataView (dt ); // Save the able to DataView to filter the data TreeNode tn; // create a TreeView node (TreeNode ), to add the retrieved data to the node, foreach (DataRowView row in dv) {tn = new TreeNode (); // create a new node (named as an instance) tn. value = row [id]. toString (); // Value of the node, which is generally the id Value of the database tn. text = row [text]. toString (); // The Node Text. The Node Text displays TreeView1.Nodes. add (tn); // Add the node to the TreeView }}

2. Step-by-Step loading and binding of multi-level nodes

Related code:

<asp:TreeView ID="TreeView1" runat="server" ImageSet="Simple" CssClass="gridview_m"                                                OnSelectedNodeChanged="TreeView1_SelectedNodeChanged" NodeIndent="35" ExpandDepth="0"                                                ShowLines="True" OnTreeNodeExpanded="TreeView1_TreeNodeExpanded">                                            </asp:TreeView>

Protected void bind () // data binding of TreeView {string sqlstr = ConfigurationManager. appSettings ["constr"]; SqlConnection conn = new SqlConnection (sqlstr); conn. open (); string sqlsel = "select * from tDataSheetDirectory"; SqlCommand cmd = new SqlCommand (sqlsel, conn); SqlDataAdapter sda = new SqlDataAdapter (cmd ); dataTable dt = new DataTable (); sda. fill (dt); string id = "DataSheetDirectoryID"; string text = "DirectoryName"; string pid = "FatherID"; DataView dvtop = new DataView (dt); // Add the root node TreeNode tntop = new TreeNode (); dvtop. rowFilter = "FatherID is null"; foreach (DataRowView row in dvtop) {tntop. value = row [id]. toString (); tntop. text = row [text]. toString (); TreeView1.Nodes. add (tntop);} sda. dispose (); cmd. dispose (); conn. close (); Bind_ TV (dt, tntop, tntop. value, id, pid, text);} protected vo Id Bind_ TV (DataTable dt, TreeNode p_Node, string pid_val, string id, string pid, string text) // recursive binding of TreeView {DataView dv = new DataView (dt ); // Save the able to DataView to filter data // create a TreeNode node for the TreeView, so that the retrieved data can be added to the node. // The following is a Trielement operator, if the parent id is empty, it is the query condition for building "parent id field is null". Otherwise, the query condition for "parent id field = parent id field value" is string filter = string. isNullOrEmpty (pid_val )? Pid + "is null": string. format (pid + "= '{0}'", pid_val); dv. rowFilter = filter; // use DataView to filter data and select the data foreach (DataRowView row in dv) {TreeNode tn = new TreeNode (); tn. value = row [id]. toString (); // The Value of the node Value is tn. text = row [text]. toString (); // node Text value p_Node.ChildNodes.Add (tn); // Add the node to the upper-level node} protected void TreeView1_SelectedNodeChanged (object sender, EventArgs e) {ViewState ["DataSheetState"] = 0; int directoryid = Convert. toInt32 (this. treeView1.SelectedNode. value); string sqlstr = ConfigurationManager. appSettings ["constr"]; SqlConnection con1 = new SqlConnection (sqlstr); con1.Open (); string strfac1 = "select * from tDataSheetDirectory where DataSheetDirectoryID = '" + directoryid + "'"; sqlCommand cmd1 = new SqlCommand (strfac1, con1); SqlDataReader dr1 = secrets 1.executereader (); dr1.Read (); if (dr1.HasRows) {// Label1.Text = dr1 ["DirectoryName"]. toString () ;}dr1.dispose (); Prepare 1.dispose (); con1.Close (); // ViewState ["DataSheetDirectoryID"] = this. treeView1.SelectedNode. value; // GridViewBind ("select * from tDataSheet where FatherDirID = '" + this. treeView1.SelectedNode. value + "'"); GridViewBind ("select tDataSheetDirectory. *, tDataSheet. * from tDataSheetDirectory, tDataSheet where tDataSheet. fatherDirID = '"+ this. treeView1.SelectedNode. value + "'and tDataSheet. fatherDirID = tDataSheetDirectory. dataSheetDirectoryID and tDataSheetDirectory. hidden = ''"); for (int I = 0; I <this. treeView1.Nodes. count; I ++) {// if (this. treeView1.SelectedValue = this. treeView1.Nodes [I]. value) {// if the root node is selected, expand this. treeView1.SelectedNode. expanded = true;} else {// If the selected node is not the root node for (int j = 0; j <this. treeView1.SelectedNode. parent. childNodes. count; j ++) {// this causes all peer nodes of the selected node to contract this. treeView1.SelectedNode. parent. childNodes [j]. collapseAll () ;}/// then expand the selected node and all its parent nodes // this. treeView1.SelectedNode. parent. expanded = true; this. treeView1.SelectedNode. expanded = true ;}} protected void treeviewinclutreenodeexpanded (object sender, TreeNodeEventArgs e) {string sqlstr = ConfigurationManager. appSettings ["constr"]; SqlConnection conn = new SqlConnection (sqlstr); conn. open (); TreeNode exnode = e. node; // expand the Node int fid = Convert. toInt32 (exnode. value); // expand the node ID string sqlsel = "select * from tDataSheetDirectory"; SqlCommand cmd = new SqlCommand (sqlsel, conn); SqlDataAdapter sda = new SqlDataAdapter (cmd ); dataTable dt = new DataTable (); sda. fill (dt); NodeExpand (dt, exnode, fid);} protected void NodeExpand (DataTable dt, TreeNode p_node, int pid) {int nextnodec = p_node.ChildNodes.Count; // number of lower-level nodes for (int I = 0; I <nextnodec; I ++) {TreeNode tn = p_node.ChildNodes [I]; tn. childNodes. clear (); int nodevalue = Convert. toInt32 (tn. value); DataView Newcastle = new DataView (dt); // you can call this operation to obtain the whole table. rowFilter = "FatherID = '" + nodevalue + "'"; TreeNode tnn; // subnode foreach (DataRowView rown in OPC) {tnn = new TreeNode (); tnn. text = rown ["DirectoryName"]. toString (); tnn. value = rown ["DataSheetDirectoryID"]. toString (); tn. childNodes. add (tnn );}}}

C # treeview recursively bind data

{
SqlDataAdapter adp = new SqlDataAdapter ("select * from tb_table", connString );
DataTable dtData = new DataTable ();
Adp. Fill (dtData );
TreeView TV; // tree control
TV. Nodes. Clear ();
// Obtain Level 1 Data
DataRow [] drRoot = dtData. Select ("len (varid) = 3 ");
Foreach (DataRow dr in drRoot)
{
TreeNode tn = new TreeNode ();
Tn. Text = dr ["Name"]. ToString ();
AppendChild (tn, dr ["varid"]. ToString ());
TV. Nodes. Add (tn );
}
}
// Recursively bind data
Private void AppendChild (TreeNode tnParent, string varid)
{
DataRow [] drs = dtData. Select ("substring (varid, 0," + varid. length + "and len (varid) =" + varid. length + 3 ));
Foreach (DataRow dr in drs)
{
TreeNode tn = new TreeNode ();
Tn. Text = dr ["Name"]. ToString ();
AppendChild (tn, dr ["varid"]. ToString ());
TnParent. ChildNodes. Add (tn );
}
}

This is probably the case. Let's modify it.

C # Is the TreeView bound to the database?

Recursive Method.
// <Summary>
/// TreeView Data Binding
/// </Summary>
/// <Param name = "list"> </param>
Protected void CreateTreeView ()
{
TreeNode rootNode = new TreeNode ();
RootNode. Text = "all ";
RootNode. Value = "-1 ";
BasicTypeTreeView. Nodes. Add (rootNode );

BasicInformationManager BasicManager = new BasicInformationManager ();
Var tlist = BasicManager. GetAllBasicInfoTypes ();
Foreach (Model. BasicInforType mtype in tlist)
{
If (mtype. ParentID = 0)
{
TreeNode Node = new TreeNode ();
// Add the root node
Node. Text = mtype. BasicTypeName;
Node. Value = mtype. ID. ToString ();
Node. ToolTip = "encoding" + mtype. BasicCode;
GetSubNode (ref Node, mtype. ID );
RootNode. ChildNodes. Add (Node );
}
}
}

/// <Summary>
/// Obtain the treeView subnode
/// </Summary>
/// <Param name = "node"> </param>
/// <Param name = "item"> </param>
Public void getSubNode (ref TreeNode node, int item)
{
BasicInformationManager... the remaining full text>